Transformation strengthened cold-machined high-strength steel, steel tube and manufacturing method thereof

Abstract

The invention provides a transformation strengthened cold-machined high-strength steel, a steel tube and a manufacturing method thereof. The steel comprises the following chemical components in percentages by weight: 0.11-0.17% of C, 0.1-0.5% of Si, 0.5-2.0% of Mn, 0.01-0.05% of Al, 0.001-0.01% of Ca, less than or equal to 0.015% of P, less than or equal to 0.003% of O, less than or equal to 0.005% of S, less than or equal to 0.004% of N, and the balance of Fe and inevitable impurities, and meanwhile, the following relationship is required to be satisfied: 0.3%<C*Mn+Cr+2Mo<1.1%. The cold-machined high-strength steel tube is prepared by a transformation strengthened and strain strengthened composite process, the yield strength of the steel tube reaches 890 MPa or above, the elongation is greater than or equal to 10%, the structure of the steel tube is deformation ferrite and tempered martensite, and damping performance is excellent.

Description

technical field [0001] The present invention relates to high-strength steel pipes, in particular to a phase-transition-strengthened cold-worked high-strength steel, a steel pipe and a method for manufacturing a steel pipe, in particular to cold-drawn / cold-rolled high-strength steel with a yield strength of 890 MPa or more produced by a phase-change strengthening process, A steel pipe and a method for manufacturing the steel pipe. Background technique [0002] It is an inevitable trend of social development that construction machinery and steel structures are developing in the direction of large load-bearing and lightweight. Especially for steel structural parts that bear high loads, increasing the strength grade of materials can not only reduce the self-weight of the structure, reduce material costs, but also help improve the bearing capacity of steel structural parts. Therefore, how to increase the strength of steel at low cost and efficiently has always been the goal purs...

AI Technical Summary

Problems solved by technology

Due to the high-frequency induction heating and quenching, only automobile anti-collision pipes with a maximum wall thickness of 2.5mm can be produced. It is extremely difficult to produce high-strength steel pipes with large diameters and wall thicknesses greater than 3mm.

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